Configuration Attributes

The following table lists the configuration attributes that you can get and set. Except where noted, sizes are in MB, and times are in seconds.

Table 0-17  Configuration Attributes 

Attribute

Default

Range

Description

ConfigPath

/etc/opt/SUNWhadb/dbdef

 

(get only) Location of configuration files used internally by the HADB.

ConnectionTrace

FALSE

 

If true, records a message in the HADB history files when a client connection (JDBC, ODBC) is initiated or terminated.

CoreFile

FALSE

 

The default value should not be changed.

DatabaseName

hadb

 

(get only) Name of the database.

DataBufferPoolSize

200

16MB - 2GB

Size of the data buffer pool allocated in shared memory.

DataDeviceSize

none

Maximum is the smaller of 256 GB or the maximum operating system file size, minimum is:

(4 x LogbufferSize + 16MB) / NumberOfDatadevices

HADB uses this amount of space internally. Therefore, this space is not available for storing user data.

The size of each data device used by an HADB node.

DataDeviceSize is equal to:

TotalDatadeviceSizePerNode / NumberOfDatadevices

Therefore, TotalDatadeviceSizePerNode and DataDeviceSize are mutually dependent: changing one changes the other.

The recommended size is four times the expected size of the user data, based on the number of users and the size of each user record.

DevicePath

/var/tmp

 

(get only) Location of the devices. There are three devices: the DataDevice, the NiLogDevice (node internal log device), and the RelalgDevice (relational algebra query device).

EagerSessionThreshold

50 (% of NumberOfSessions)

0 - 100

Determines whether normal or eager idle session expiration is used.

In normal idle session expiration, sessions that are idle for more than SessionTimeout seconds are expired.

When the number of concurrent sessions exceeds the EagerSessionThreshold percentage of the maximum number of sessions, sessions that are idle for more than EagerSessionTimeout seconds are expired.

EagerSessionTimeout

120

0 - 2000000

Amount of time a database connection can be idle before it expires when eager session expiration is used.

EventBufferSize

0

0MB - 2GB

Size of the event buffer, where database events are logged. If set to 0, no event buffer logging is performed.

During failures, the event buffer is dumped. This gives valuable information on the cause of the failures and is useful during trial deployment.

Writing events to memory has a performance penalty.

HistoryPath

/var/tmp

 

(get only) Location of the HADB history files, which contain information, warnings, and error messages.

InstallPath

parent of the directory where hadbm resides: install_dir/SUNWhadb/4/

 

(get only) Location of the HADB executable files.

InternalLogbufferSize

12

4MB - 128MB

Size of the node internal log device, which keeps track of operations related to storing data.

JdbcUrl

none

 

(get only) The JDBC connection URL for the database.

LogbufferSize

48

4MB - 2GB

Size of the log buffer, which keeps track of operations related to data.

ManagementProtocol

ssh

rsh, ssh

(get only) Protocol used between the hadbm command and the database nodes.

MaxTables

1100

100 - 1100

Maximum number of tables allowed in an HADB database.

NumberOfDatadevices

1

1 - 8

(get only) Number of data devices used by an HADB node.

NumberOfLocks

50000

20000 - 2147483647

Number of locks allocated by an HADB node.

NumberOfSessions

100

1 - 10000

Maximum number of sessions (database connections) that can be opened for an HADB node.

Portbase

15200

10000 - 63000

(get only) Base port number used to create different port numbers for different HADB processes.

RelalgdeviceSize

128

32MB - 2GB

Size of the device used in relational algebra queries.

SessionTimeout

1800

0 - 2000000

Amount of time a database connection can be idle before it expires when normal session expiration is used.

SQLTraceMode

NONE

NONE, SHORT, FULL

Amount of information about executed SQL queries written to the history files.

If SHORT, login and logout of SQL sessions are recorded. If FULL, all SQL queries being prepared and executed, including parameter values, are recorded.

StartRepairDelay

20

0 - 100000

Maximum time a spare node allows for a failed active node to perform a node recovery. If the failed node cannot recover within this time interval, the spare node starts copying data from the failed node’s mirror and becomes active. Changing the default value is not recommended.

StatInterval

600

0 - 1000

Interval at which an HADB node writes throughput and response time statistics to its history file. To disable, set to 0.

An example statistics line is as follows:

"Req-reply time: # 123, min= 69 avg= 1160 max= 9311 %=100.0"

The # is the number of requests serviced over the StatInterval. The next three numbers are the minimum, average, and maximum time in microseconds taken by transactions completed over the StatInterval. The % is the number of transactions completed successfully within 15 milliseconds over the StatInterval.

SyslogFacility

local0

local0, local1, local2, local3, local4, local5, local6, local7, kern, user, mail, daemon, auth, syslog, lpr, news, uucp, cron, none

Facility used when reporting to syslog (see man syslog for details). The syslog daemon should be configured (see man syslogd.conf for details).

Use a facility that is not in use by other applications running on the same machine.

Set to none to disable syslog logging.

SysLogging

TRUE

 

Set to true if an HADB node should write any information to the operating system’s syslog files.

SysLogLevel

warning

none, alert, error, warning, info

Lets you to fine tune which HADB messages are reported to the operating system’s syslog files.

Higher levels include lower levels. For example, the error level includes alert messages, and the info level includes all messages.

SyslogPrefix

HADB

 

Text string that is prepended to all syslog messages written by the HADB.

TakeoverTime

10000 (milliseconds)

500 - 16000

Time between when a node fails and when its mirror takes over. Changing the default value is not recommended.

TotalDatadeviceSizePerNode

none

Maximum is the smaller of 256 GB or the maximum operating system file size, minimum is:

4 x LogbufferSize + 16MB

HADB uses this amount of space internally. Therefore, this space is not available for storing user data.

Sum of the sizes of all data devices used by an HADB node.

TotalDatadeviceSizePerNode is equal to:

DataDeviceSize x NumberOfDatadevices

Therefore, TotalDatadeviceSizePerNode and DataDeviceSize are mutually dependent: changing one changes the other.


Clearing and Archiving History Files

HADB history files contain a record of database operations and error messages. The location of these files is determined by the --historypath option of the hadbm create command. The default location is /var/tmp. These files have names of the format dbname.out.nodeno. For details about hadbm create, see "Creating a Database".

These history files grow over time. To save space and prevent files from getting too large, you should periodically clear and archive older history files. To clear the history files of a database, use the hadbm clearhistory command. The syntax is as follows:

hadbm clearhistory [--saveto=path] [dbname]

The default dbname is hadb.

Use the --saveto or -o option to specify a directory if you want to store the old history files. This directory must have write permissions set.

Each message in the history file contains the following information:

Messages about resource shortages contain HIGH LOAD.

You do not need a detailed knowledge of all the various types of entries in the history file. If for any reason you need to study a history file in greater detail, you should obtain help from Sun customer support. See “Using Sun Customer Support for the HADB” on page 70.


Recovering from Session Data Corruption

The following are indications that session data may be corrupted:

To bring the session store back to a consistent state if you determine that the data has been corrupted, do the following:

  1. Clear the session store.
  2. If clearing the session store doesn’t work or you continue to see errors in the server log, reinitialize the data space on all the nodes and clear the data in the database.
  3. If clearing the database doesn’t work, delete and then recreate the database. See "Removing a Database" and "Creating a Database".


Environment Variables

This table lists environment variables that correspond to hadbm command options.

Table 0-18  HADB Options and Environment Variables 

Long Form

Short Form

Default

Environment Variable

--configpath

-c

/etc/opt/SUNWhadb

$HADBM_CONFIGPATH

--datadevices

-a

1

$HADBM_DATADEVICES

dbname

none

hadb

$HADBM_DB

--dbpassword

-p

none

$HADBM_DBPASSWORD

--dbpasswordfile

-F

none

$HADBM_DBPASSWORDFILE

--devicepath

-d

/var/opt/SUNWhadb

$HADBM_DEVICEPATH

--devicesize

-z

none

$HADBM_DEVICESIZE

--echo

-e

FALSE

$HADBM_ECHO

--fast

-F

FALSE

$HADBM_FAST

--force

-f

FALSE

$HADBM_FORCE

--help

-?

FALSE

$HADBM_HELP

--historypath

-t

/var/tmp

$HADBM_HISTORYPATH

--hosts

-H

none

$HADBM_HOSTS

--installpath

-n

parent of the directory where hadbm resides: install_dir/SUNWhadb/4/

$HADBM_INSTALLPATH

--interactive

-i

TRUE

$HADBM_INTERACTIVE

--no-refragment

-r

FALSE

$HADBM_NOREFRAGMENT

--portbase

-b

15200

$HADBM_PORTBASE

--quiet

-q

FALSE

$HADBM_QUIET

--repair

-R

TRUE

$HADBM_REPAIR

--rolling

-g

TRUE

$HADBM_ROLLING

--saveto

-o

none

$HADBM_SAVETO

--set

-S

none

$HADBM_SET

--spares

-s

0

$HADBM_SPARES

--startlevel

-l

normal

$HADBM_STARTLEVEL

--version

-V

FALSE

$HADBM_VERSION

--yes

-y

FALSE

$HADBM_YES


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